In these years, a high-capacity and compact removable recording medium has come to be widely used. An example of such a recording medium is an IC memory card (hereinafter referred to as memory card) that can be randomly accessed, such as a flash memory. Further, also have been developed are recording apparatuses and reproducing apparatuses for recording and reproducing various types of content on and from the memory card.
In accordance with this, many types of memory cards have been developed. For example, there are now many types of flash memories such as CompactFlush (registered trademark) (CF), Smart Media (registered trademark) (SM), memory stick, MultimediaCard (MMC), and SecureDigital (SD). Some types of the memory cards comply with a technique for protecting copyrights, thus facilitating the circulation of digital content.
Such a memory card can be used by being attached to a plurality of different content recording apparatuses or content reproducing apparatuses. For example, a SD memory card can allow a content to be recorded on and reproduced from the SD memory card when inserted into various types of content reproducing apparatuses respectively having built-in SD card slots. These content reproducing apparatuses include a PC (personal computer), a digital video camera (DVC), a printer, a digital camera, an audio player, an IC recorder, a car audio system, a car navigation system, a portable terminal (such as an e-mail terminal, a portable phone, and a PHS), and a facsimile machine.
A typical conventional recording medium is arranged so that data is recorded on the recording medium by a recording apparatus and reproduced from the memory card by a reproducing apparatus that is a companion to the recording apparatus. Namely, a reproducing apparatus must be arranged so as to reproduce data recorded by a companion recording apparatus. For example, data recorded on a video tape by a video cassette recorder can be reproduced by any video cassette recorder.
However, since some devices such as digital camera now employ different encoding systems according to types of the device, there are some cases where a content cannot be reproduced by a digital camera whose type is different from that of a digital camera that recorded the content.
In order to solve the foregoing problems, Japanese Unexamined Patent Publication No. 2000-341629 (Tokukai 2000-341629; published on Dec. 8, 2000), for example, suggests a certain technique. In this technique, in a case where data taken by a digital camera (DA) is recorded on a recording medium (A) and then copied to a recording medium (B) using a digital camera (DB) whose type is different from that of the digital camera (DA), only data that is reproducible by the digital camera (DB) is selected from the data recorded on the recording medium (A) and copied to the recording medium (B).
Namely, in the technique described in Tokukai 2000-341629, unique information of the manufacturer is recorded in an area of header and manufacturer information of the image data that is taken by the digital camera (DA), as shown in FIG. 20(a). The digital camera (DB) reads out the unique information from the recording medium (A) so as to judge whether or not the image data can be reproduced by the digital camera (DB). Then, only image data that can be reproduced by the digital camera (DB) is automatically selected from the image data and copied to the recording medium (B).
Further, Japanese Patent No. 3152903 (published on Dec. 4, 1998) suggests a technique used in a digital camera complying with a plurality of decoding systems. In this technique, control information (such as encoding system and shooting condition) with respect to each image in the image data that is recorded on a recording medium is read so that a decoding system corresponding to encoded data of the images recorded on the recording medium is selected before the image data is reproduced.
In other words, the arrangement described in Japanese Patent No. 3152903 is provided with a control section for reading the control information, such as encoding system, which is added to the image data recorded on the recording medium as shown in FIG. 20(b). The control section selects from a plurality of built-in decoding devices of the digital camera, a decoding device corresponding to an encoding system of the encoded data, so as to reproduce the image data.
Further, as also shown in FIG. 19, a current memory card can allow data to be recorded on and reproduced from the memory card when inserted into any device having a corresponding built-in card slot, such as both a DVC and a facsimile machine which have completely different uses from each other, for example, other than the digital camera.
In this example, it is assumed that the DVC records an image. If, in advance, a taken image is intended to be sent a desired person via the facsimile machine, the DVC records the image using a still image mode and using a selected encoding system that allows the facsimile machine to reproduce the image. Here, by recording encoded data of the taken image on the memory card and inserting the memory card into the facsimile machine, it is possible to allow the facsimile machine to reproduce the encoded data, so as to send the taken image to the desired person.
However, in the cases as described above, before taking the image, the user is required to know and designate the type (such as moving image, still image, sound, audio, and text) and encoding system of content that the reproducing apparatus can reproduce.
Further, even if two devices, such as a portable phone and a DVC both capable of handling moving images, can handle moving images and comply with the same encoding method, the two devices may differ from each other in terms of conditions including a processing capability such as a image size, bit rate, and frame rate, as well as the number of mounted encoding tools. Thus, if moving images taken by the DVC is to be reproduced by a portable phone having a limited processing capability, it is necessary to designate encoding conditions in accordance with the processing capability of the reproducing apparatus (portable phone).
In order to guarantee compatibility between different types of devices, the MPEG-2 and MPEG-4 standards employ a concept of profile and level, and compatibility mode is defined in the standard for SD card. However, the compatibility defined here is such that a device supporting a high profile, level, or mode must reproduce a content complying with a lower profile, level, or mode.
Therefore if a profile, level, or mode of the recording apparatus is higher than that of the reproducing apparatus, it is necessary to encode and record a content in accordance with the profile, level, or mode of the reproducing apparatus so as to allow the reproducing apparatus to reproduce the recorded content. However, it is difficult for the user to know all the profile, level, or mode which is defined in a plurality of types.
Further, the two conventional techniques as described above are inconvenient because it is not possible to know whether or not the content recorded on the memory card can be reproduced by a reproducing apparatus until the memory card is actually inserted into the reproducing apparatus.
In view of the foregoing problems, an example embodiment presented herein has a feature to provide a content recording/reproducing system, a content reproducing apparatus, a content recording apparatus, and a content re-coding apparatus which are capable of reproducing a content recorded on a recording medium without requiring the user to designate a type of content, an encoding method of content, an encoding parameter, or the like.